Gastroparesis is a disorder of delayed gastric emptying in the absence of mechanical obstruction that is more common in diabetic patients. Pistacia atlantica gum is one of the effective herbs in the treatment of stomach disorders. The aim of this study is to investigate the effect of Pistacia atlantica gum on diabetic gastroparesis symptoms. The target population are type 1 or 2 diabetic patients older than 18 years with the clinical symptoms of gastroparesis who are referred to the clinic of Imam Reza hospital. Patients, who are evaluated about other criteria by a gastroenterologist and endocrinologist and are willing to participate, enroll in the study. The sample size is 48. The patients will randomly be divided into two groups by block randomization method. In both groups, appropriate dietary advice with diabetic gastroparesis is given to the patients. In addition, patients in intervention group receive Pistacia atlantica gum and the control group receive placebo. This study is done Triple blind. Symptoms will be recorded by GCSI standard questionnaire (Gastroparesis cardinal symptom index). The questionnaire evaluates six groups of symptoms, including nausea and vomiting, filling of fullness and early satiety, bloating, upper abdominal pain, lower abdominal pain, heartburn and belching. Hematology and biochemistry blood tests including Complete blood count, Fasting blood sugar, Glycated hemoglobin, Triglycerides, Cholesterol, Low-density lipoprotein, High-density lipoproteins, Aspartate aminotransferase, Alanine aminotransferase, creatinine and Blood urea nitrogen will be done at baseline and 4 weeks later to assess the patients condotion and the possible treatment side effects and also the effect of gum on the control of blood sugar and fat and also liver and renal parameters in patients with diabetic gastroparesis.